Needle devices are used throughout the medical industry for the injection and withdrawal of a wide variety of fluids and solutions into and from the human body. Because of the numerous potential hazards associated with the handling and manipulation of bodily fluids, and particularly blood, there are a number of known safety features that are frequently incorporated into various types of needle devices to protect the practitioner from accidental exposure to the needle.
Other prior safety needle devices having a retractable sheath require multi-component retraction and locking elements. Conventional retraction syringe assemblies often do not incorporate reuse prevention features, and thus, the retraction mechanism may be reset so the syringe barrel may be reused. The reuse of syringe assemblies without sterilization or sufficient sterilization is believed to facilitate the transfer of contagious diseases. Further, the retraction features of conventional syringes also often require the user to actively activate the retraction mechanism. Accordingly, the chance of human error in failure to activate or properly activate the retraction mechanism can lead to continued exposure of needles.
Prior retracting sheath safety needle devices have been developed to include a single-use cover assembly that obscures a substantial majority or an entirety of an injection needle from view before, during, and after an injection procedure. However, many injection procedures require that the practitioner know precisely the location and depth to which the needle is inserted in the patient's tissue to be sure that medication is delivered to an appropriate location.
There is a need in the art to provide a safety needle device having a passive activation mechanism that overcomes the deficiencies of the known retracting sheath safety needle devices and which allows for low part count, low part complexity, clear and unobstructed view of needle through sheath, relatively compact design and no rotation of the sheath during use.